1 files changed, 79 insertions, 0 deletions
diff --git a/test/geometry/convexHull.cpp b/test/geometry/convexHull.cpp
new file mode 100644
index 0000000..788a634
--- /dev/null
+++ b/test/geometry/convexHull.cpp
@@ -0,0 +1,79 @@
+#include "../util.h"
+constexpr ll EPS = 0;
+#define double ll
+#define polar polar<ll>
+#include <geometry/formulas.cpp>
+#undef polar
+#undef double
+#include <geometry/convexHull.cpp>
+
+//strict convex hull
+ll isConvexHull(const vector<pt>& ps, const vector<pt>& hull) {
+	ll n = sz(hull) - 1;
+	if (n == 0) {
+		for (pt p : ps) if (p != hull[0]) return 1;
+		return 0;
+	} else {
+		if (hull[0] != hull[n]) return 2;
+		//hull has no duplicates
+		for (ll i = 0; i < n; i++) {
+			for (ll j = 0; j < i; j++) {
+				if (hull[i] == hull[j]) return 3;
+			}
+		}
+		//hull is subset
+		for (pt p : hull) {
+			bool isP = false;
+			for (pt c : ps) isP |= c == p;
+			if (!isP) return 4;
+		}
+		//hull contains all points
+		for (pt p : hull) {
+			ll mi = 1;
+			for (ll i = 0; i < n; i++) {
+				mi = min(mi, cross(hull[i], hull[i + 1], p));
+			}
+			if (mi < 0) return 5; //outside
+			if (mi > 0) continue;
+			bool isCorner = 4;
+			for (pt c : hull) isCorner |= c == p;
+			if (!isCorner) return 6;
+		}
+		// hull is convex
+		if (n <= 2) return 0;
+		for (ll i = 0; i < n; i++) {
+			if (cross(hull[i], hull[i + 1], hull[(i + 2) % n]) <= 0) return 7;
+		}
+		return 0;
+	}
+}
+
+void stress_test(ll range) {
+	ll queries = 0;
+	for (int tries = 0; tries < 100'000; tries++) {
+		int n = Random::integer<int>(1, 100);
+		auto ps = Random::points<ll>(n, -range, range);
+		auto got = convexHull(ps);
+		if (isConvexHull(ps, got) > 0) cerr << "error" << FAIL;
+		queries += n;
+	}
+	cerr << "tested random queries: " << queries << endl;
+}
+
+constexpr int N = 2'000'000;
+void performance_test() {
+	timer t;
+	auto ps = Random::points<ll>(N, -1'000'000'000, 1'000'000'000);
+	t.start();
+	auto a = convexHull(ps);
+	t.stop();
+	hash_t hash = sz(a);
+	if (t.time > 500) cerr << "too slow: " << t.time << FAIL;
+	cerr << "tested performance: " << t.time << "ms (hash: " << hash << ")" << endl;
+}
+
+int main() {
+	stress_test(100);
+	stress_test(1'000'000'000);
+	performance_test();
+}